5 mistakes when buying shower seals — and how to avoid them
The most common pitfalls when ordering shower seals online — and how to dodge them.
We've seen hundreds of wrong orders
From our research we know the recurring pitfalls. Here are the five mistakes almost everyone makes at least once — and how to avoid them.
Mistake 1: glass thickness not measured
The classic. You order a 6 mm seal because "most are 6 mm". Then your shower turns out to be 8 mm — the seal sits too loose, water leaks through.
Fix: measure before buying. Calliper, glass thickness gauge or, in a pinch, ruler & smartphone photo.
→ Tutorial: determine glass thickness
Mistake 2: wrong magnetic angle
You order a "shower magnetic seal" because surely that's unambiguous. The package contains a 90° seal. Your shower is a corner entry — you needed 135°.
Fix: clarify the door situation before buying:
- Door at right angle to fixed panel: 90°
- Two doors meeting in the middle: 135°
- Door closes flush against fixed panel: 180°
Mistake 3: not enough length ordered
You measure exactly 1,900 mm glass height and order exactly 1,900 mm of seal. On installation: the cut edge isn't perfectly straight, the seal redistributes by a few millimetres while threading — you end up 5 mm short.
Fix: always add 10 % reserve. For 1,900 mm, order 2,100 mm or just go for the standard 2 m length. You can trim a too-long seal easily — you can't extend a too-short one.
Mistake 4: magnets installed inverted
When replacing magnetic seals, many people install the new seal — and the door pushes itself away from the fixed panel instead of attracting.
What's happening: if both magnetic seals expose the same polarity outward, they neutralise each other or repel.
Fix: before installation, magnet test with a steel spoon. Hold the spoon to the magnet side — it must stick. Then make sure the magnet sides face each other when the door is closed. When in doubt: close the door first with the seal on one side only, check where the magnet should go.
Mistake 5: universal profile in a brand-specific groove
You have an older Kermi or Hüppe shower and order a cheap universal profile from Amazon. On installation: doesn't fit the profile groove. The brand uses a specific click geometry that universal seals aren't compatible with.
Fix:
- For newer premium brands (Sprinz, HSK Atelier): order original from the manufacturer.
- For standard ranges (Schulte Express, Kermi Cada XS): try universal — usually fits.
- In doubt: buy a cheap universal seal, check that the profile width matches — you have the right of return anyway.
Bonus: the secret sixth mistake
Not replacing both seals on the same glass at once.
If your magnetic seal is worn, the floor seal on the same glass is probably not great either — same age. Yet many people only replace the obviously broken one and find themselves annoyed three months later about the second.
Strategy: if you're working on the glass anyway, replace both seals at once. Material costs €5–15 extra, time barely more. Saves you a second replacement effort.
How to avoid all five mistakes at once
→ Launch the configurator. It asks you for every relevant variable (shape, glass thickness, profile position, dimensions) and proposes the matching set. Including reserve calculation. Including magnetic-angle logic. Including double-seal recommendation when it makes sense.
Saves research, saves wrong orders.